Design Of Carbon Dioxide Measurement And Control System Based On The SCM In The Greenhouse

This paper presents a measurement and control system of carbon dioxide in the greenhouse. The system can increase the crop yields by control the content of carbon dioxide. This paper describes hardware design, software programming and debugging process of this system.The system bases on the STC89C516RD+ Single Chip Microcontroller (SCM), consist of sensors, signal conditioning circuits, data storage circuit, USB control circuit, display circuit and communication circuit. It uses the oxygen and carbon dioxide sensors to determinate the content of oxygen and carbon dioxide in the greenhouse, uses the pressure sensor to get the gas pressure in the pipeline of carbon dioxide generator. The signal of oxygen and gas pressure will be transformed by the analog-to-digital conversion and put it into the SCM. The signal of carbon dioxide is picked through the serial interface of the SCM. The SCM analyses the data and controls the on-off of the magnetic value by the relay. The magnetic valve can control the carbon dioxide generator to get the aim of control the content of the carbon dioxide. The date, time, content of carbon dioxide and oxygen will be stored into the E2PROM chip every ten minutes, and downloaded into the UDisk through the USB connector for data analysis. This project provides a'12864 LCD'which can display the information for the staff to change the parameters by the current conduction. This project also provides a connector for the PC, to collect and display the data by the PC software. This project is easy to install, work stable and the maintainability is well during the using time.